A new method for producing iron is not only faster and cheaper, but according to Chinese researchers, it is also better for the environment.
After more than a decade of intensive research in China, a new iron production technology is ready to revolutionize the global steel manufacturing industry.
The method involves injecting fine iron ore powder into a furnace at a very high temperature, which, according to the project’s engineers, initiates an “explosive” chemical reaction. The result is the display of bright red, glowing liquid iron droplets that pour down the furnace and collect, forming a stream of high-purity iron that can be directly used for casting or “one-step steel production.” This signifies an increase in iron production speed by 3,600 times or more.
According to researchers, this new method works especially well for low- or medium-grade iron ores, which are abundantly found in China.
Existing iron production methods are heavily dependent on high-grade iron ores, and China imports a large amount of these ores from Australia, Brazil, and Africa.
According to calculations by Zhang and his colleagues, this new technology could improve energy efficiency in China’s steel industry by more than a third. By completely eliminating the need for coal, this technology could also bring the steel industry closer to the desired goal of “near-zero carbon dioxide emissions,” according to Zhang’s team.
China’s steel production capacity is currently greater than the combined output of the rest of the world. This advantage has given China an edge in key industries such as high-speed rail, shipbuilding, and automobile manufacturing.
However, its reliance on blast furnace melting processes, which require large amounts of coke derived from coal, is a major barrier to achieving China’s ambitious carbon reduction goals.
One of the major technical challenges in realizing flash ironmaking is the lance that sprays the iron ore. The iron ore must be dispersed in a high-temperature tower with high reduction capability and a large surface area to initiate the explosion.
Zhang’s team has developed a vortex lance with exceptional uniform distribution performance, capable of injecting 450 tons of iron ore particles per hour. A reactor equipped with three of these lances can produce 7.11 million tons of iron annually. According to the paper, this lance “has now entered commercial production.”
Zhang’s journey with flash melting technology began in the 1970s when he applied it for large-scale copper production. His work earned him the first-place National Science and Technology Progress Award in 2000 and led to his selection to the Chinese Academy of Engineering in 2003.
Today, China’s copper consumption accounts for nearly 60% of global production, a testament to Zhang’s lasting impact on the industry.
While the idea of using this process for iron production originated in the United States, it was Zhang’s team that invented a flash melting technology capable of directly producing liquid iron. They received a patent for it in 2013 and spent the next decade refining the method.
“Laboratory and pilot tests have proven that this process is feasible,” Zhang wrote. According to government statistics, the success rate for new technologies that have passed pilot testing in China is over 80%.
For most of recorded history, China has been a leader in iron and steel production. As the Tang Dynasty poet, Li Bai (701-762), once described, the large iron-producing furnaces in an iron-making city in what is today Anhui Province lit up the night sky.
According to estimates by American historian Robert Hartwell, during the Song Dynasty in the 11th century, China’s iron production reached 150,000 tons per year – a figure that was not achieved in all of Europe until after the beginning of the Industrial Revolution in the 18th century.
Steel World Review
